Anxiety disorders are among the most common diagnosable psychiatric disorders that can ultimately lead to physical symptoms, and they account for a majority of primary care and emergency room visits. In most cases, people are unaware that they have an anxiety disorder until a formal diagnosis is made. Anxiety disorders are under-recognized and often untreated in the medical community, which causes significant stress and distress for those who have them. According to the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5), anxiety disorders include features of excessive fear and anxiety and related behavioral disturbances.1 A hypothesis for the pathophysiology of anxiety disorders has been proposed; some theorize that it involves the interaction of biopsychologic factors, including genetic vulnerability, which can cause stress or trauma in certain situations. In addition, there are specific mediators of the symptoms of anxiety disorder, such as the neurotransmitters norepinephrine and serotonin. Peripherally, the autonomic system has the ability to mediate many of the classical symptoms of an anxiety disorder.2
Generalized anxiety disorder
Generalized anxiety disorder (GAD) is considered to be the most common anxiety disorder, and it is characterized by an unrealistic or excessive anxiety occurring more days than not for at least 6 months.3 The clinical features of GAD are comparable with many other anxiety disorders as a result of its manifestations, which include insomnia, irritability, trembling, dry mouth, or clammy hands, among others.4
With regard to drug treatment of GAD, selective serotonin reuptake inhibitors (SSRIs) are considered to be the first-line treatment option, as they have a slower onset of action.5 Other antidepressants, such as venlafaxine, can be used at a starting dose of 75 mg/d; in individuals with severe anxiety or panic attacks, it should be initiated at a lower dose of 37.5 mg/d. Buspirone can also be used; it usually takes 3 to 6 weeks at a dosage of 10 to 20 mg three times daily to become effective. Compared with benzodiazepines, which can also be used to treat GAD, buspirone is not associated with dependence, withdrawal effects, or abuse.4 Tricyclic antidepressants (TCAs) are also effective in the treatment of GAD, but an adverse side-effect profile limits their use. The benzodiazepines can also be used for the treatment of GAD. They have a rapid onset and a somewhat favorable side-effect profile, but they are typically only recommended for acute anxiety reactions, and not for the treatment of chronic GAD.6
A panic disorder primarily consists of an intense fear or sense of impending doom that is intolerable and unbearable. Patients feel an intense terror or fear associated with the disorder.3,4 Pharmaceutical treatment of panic disorder is somewhat similar to that of GAD, in that SSRIs (eg, sertraline, fluoxetine, and paroxetine) are considered to be the first-line treatments. They are typically started at lower doses when compared with the doses that are used to treat depression because those doses can exacerbate the anxiety in patients with panic disorder.5
The same low dosing regimen also applies to the use of TCAs because of their ability to exacerbate panic symptoms. With regard to TCAs, imipramine is the best-studied medication and should be initiated at 10 to 25 mg/d, with a gradual increase up to 100 to 200 mg/d if necessary and tolerated.
The TCAs can be associated with cardiovascular complications, and the use of monoamine oxidase inhibitors can cause hypertensive crisis, so these agents are not frequently used. Benzodiazepines can be used in combination with TCAs or SSRIs during the initial phase of treatment for a panic disorder, as they are very effective, especially if a person is not responsive to other therapies, but this should be done with the understanding that it may not be effective for long-term use.
Along with the use of pharmacologic agents, nonpharmacologic interventions, in the form of psychotherapy, can also be used. The application of cognitive behavioral therapy, with emphasis on relaxation techniques/instructions on misinterpretation of physiologic symptoms, can also be effective. In addition, insight-oriented psychotherapy may be helpful in cases of mild anxiety.